acpi: Implement SPCR on AArch64

This commit implements an AArch64-required ACPI table: Serial
Port Console Redirection Table (SPCR). The table provides
information about the configuration and use of the serial port
or non-legacy UART interface.

Signed-off-by: Henry Wang <Henry.Wang@arm.com>

acpi_tables/src/sdt.rs

@@ -22,6 +22,15 @@ impl GenericAddress {
             address: u64::from(address),
         }
     }
+    pub fn mmio_address<T>(address: u64) -> Self {
+        GenericAddress {
+            address_space_id: 0,
+            register_bit_width: 8 * std::mem::size_of::<T>() as u8,
+            register_bit_offset: 0,
+            access_size: std::mem::size_of::<T>() as u8,
+            address,
+        }
+    }
 }
 
 pub struct Sdt {

vmm/src/acpi.rs

@@ -6,9 +6,12 @@ use crate::cpu::CpuManager;
 use crate::device_manager::DeviceManager;
 use crate::memory_manager::MemoryManager;
 use crate::vm::NumaNodes;
-#[cfg(target_arch = "x86_64")]
 use acpi_tables::sdt::GenericAddress;
 use acpi_tables::{aml::Aml, rsdp::Rsdp, sdt::Sdt};
+#[cfg(target_arch = "aarch64")]
+use arch::aarch64::DeviceInfoForFdt;
+#[cfg(target_arch = "aarch64")]
+use arch::DeviceType;
 
 use bitflags::bitflags;
 use std::sync::{Arc, Mutex};
@@ -282,6 +285,34 @@ fn create_gtdt_table() -> Sdt {
     gtdt
 }
 
+#[cfg(target_arch = "aarch64")]
+fn create_spcr_table(base_address: u64, gsi: u32) -> Sdt {
+    // SPCR
+    let mut spcr = Sdt::new(*b"SPCR", 80, 2, *b"CLOUDH", *b"CHSPCR  ", 1);
+    // Interface Type
+    spcr.write(36, 3u8);
+    // Base Address in format ACPI Generic Address Structure
+    spcr.write(40, GenericAddress::mmio_address::<u8>(base_address));
+    // Interrupt Type: Bit[3] ARMH GIC interrupt
+    spcr.write(52, (1 << 3) as u8);
+    // Global System Interrupt used by the UART
+    spcr.write(54, (gsi as u32).to_le());
+    // Baud Rate: 3 = 9600
+    spcr.write(58, 3u8);
+    // Stop Bits: 1 Stop bit
+    spcr.write(60, 1u8);
+    // Flow Control: Bit[1] = RTS/CTS hardware flow control
+    spcr.write(61, (1 << 1) as u8);
+    // PCI Device ID: Not a PCI device
+    spcr.write(64, 0xffff_u16);
+    // PCI Vendor ID: Not a PCI device
+    spcr.write(66, 0xffff_u16);
+
+    spcr.update_checksum();
+
+    spcr
+}
+
 pub fn create_acpi_tables(
     guest_mem: &GuestMemoryMmap,
     device_manager: &Arc<Mutex<DeviceManager>>,
@@ -339,15 +370,49 @@ pub fn create_acpi_tables(
         .write_slice(mcfg.as_slice(), mcfg_offset)
         .expect("Error writing MCFG table");
     tables.push(mcfg_offset.0);
+    prev_tbl_len = mcfg.len() as u64;
+    prev_tbl_off = mcfg_offset;
+
+    // SPCR
+    #[cfg(target_arch = "aarch64")]
+    {
+        let is_serial_on = device_manager
+            .lock()
+            .unwrap()
+            .get_device_info()
+            .clone()
+            .get(&(DeviceType::Serial, DeviceType::Serial.to_string()))
+            .is_some();
+        let serial_device_addr = arch::layout::LEGACY_SERIAL_MAPPED_IO_START;
+        let serial_device_irq = if is_serial_on {
+            device_manager
+                .lock()
+                .unwrap()
+                .get_device_info()
+                .clone()
+                .get(&(DeviceType::Serial, DeviceType::Serial.to_string()))
+                .unwrap()
+                .irq()
+        } else {
+            // If serial is turned off, add a fake device with invalid irq.
+            31
+        };
+        let spcr = create_spcr_table(serial_device_addr, serial_device_irq);
+        let spcr_offset = prev_tbl_off.checked_add(prev_tbl_len).unwrap();
+        guest_mem
+            .write_slice(spcr.as_slice(), spcr_offset)
+            .expect("Error writing SPCR table");
+        tables.push(spcr_offset.0);
+        prev_tbl_len = spcr.len() as u64;
+        prev_tbl_off = spcr_offset;
+    }
 
     // SRAT and SLIT
     // Only created if the NUMA nodes list is not empty.
-    let (prev_tbl_len, prev_tbl_off) = if numa_nodes.is_empty() {
+    if !numa_nodes.is_empty() {
-        (mcfg.len(), mcfg_offset)
-    } else {
         // SRAT
         let srat = create_srat_table(numa_nodes);
-        let srat_offset = mcfg_offset.checked_add(mcfg.len() as u64).unwrap();
+        let srat_offset = prev_tbl_off.checked_add(prev_tbl_len).unwrap();
         guest_mem
             .write_slice(srat.as_slice(), srat_offset)
             .expect("Error writing SRAT table");
@@ -361,7 +426,8 @@ pub fn create_acpi_tables(
             .expect("Error writing SRAT table");
         tables.push(slit_offset.0);
 
-        (slit.len(), slit_offset)
+        prev_tbl_len = slit.len() as u64;
+        prev_tbl_off = slit_offset;
     };
 
     // XSDT